Steam-generator.



N0. 842,28. PATBNTED JAN; 29, 1907.

\ W. R. WILLS.

STEAM GENERATOR.

APPLICATION FILED JULY 28, 1905.

a SHEETS-SHEET 1.

'WWNESSES v FIG. W 2E 'T 'y ATTYS No. 842,284. PATENTED JAN. 29, 1907.

' W. R. WILLS.

"STEAM GENERATOR.

APPLICATION FILED JULY 28, 1905.

3 SHEETS-SHEET 2.

F/G' Z EssEs INVENTOR PATENTED JAN. 29, 1907.

3 SHEETS-SHEET 3.

W R WILLS STEAM GENERATOR.

APPLICATION FILED JULY 28, 1905.

F/G8 warm-:gsr g UNITED STATES PATENT oF'FIoE. WALTER-RIDOUT WILLS, or SHEFFIELD, ENGLAND.

STEAM-GENERATOR.-

Specification of Letters Patent.

Application filed July 28,1905. Serial No. 271,656.

Patented J an. 29, 1907.

To all whom it may concern.-

Be it known that I,WALTER- Rmou'r WILLS, a subject of the King of Great Britain and Ireland, residing at 203 Abbeyfield road, Pitsmoor, Shefiield, in the county of York, England, have' invented certain new and useful Improvements in Steam-Generators,

(for which I have filed an application for a patent in Great Britain, N 0. 16,994, bearing date August 3, 1904,) of which the following is a specification. 4 My invention is for improvements and modifications in water-tube boilers, which'I will now describe {and it consists of a watertube boiler so constructed by the careful arrangement of parts as to intercept as far as possible heat radiation and to bring the efficiency of the structure to the highest possible point, combined 'with an air-heater so inclosed in the boiler structure as to be heated both externally and internally by the waste gases, and so to convey the heated air to the fire as toreduce the hot-air ducts to their shortest possible dimensions and at the same time to keep both heater and air-ducts entirely within the walls of the heated structure, by means obtaining the highest possible results under any given conditions.

' My invention will be better understood on referenceto the accompanying two sheets of drawings ,in which Figure 1 is a sectional elevation on the line AB, Fig. 2. Fig. 2 is an end elevation, partly in section. F' 3 is a back view of a portion of a boiler wlth the brickwork removed, showing the 'position of the superheater. Fig. 4 is.a portion of a plan view of the airheating chamber. Fig. 5 is a sectional ele plate or diaphragm; and Fig. 12 is a part longitudinal elevation of the same, partly in section. Fig. 13 is an elevation of the metal boxes fixedin the furnace-wall for airheating, and Fig. 14is a transverse section ofv the same.

The same letters refer to similar throughout the several views.

My boiler consists of one upper or steam drum (1., combined with three lower or water drums b c d, the central and lowest waterdrum 1) being connected to the steam-drum a parts by vertical pipes e and two outer water drums c and d being connected to the steamdrum by diagonal pipesf and f, respectively. 1 The fire .door or doors '9' of the boiler is or are situated beneath one of the outer drums 0, while the fire-grate his situated transversely between this outer water-drum c and the middle and lower water-drum I), while on the op osite side between the middle lower drum and the other outer or back waterdrum (1. is placed an air-heater 5 so that it is surrounded bv the hot waste gases.

The heat From the fire is conducted by suitable baffles j, coursing up and down the tubes until it reaches the outer lower waterdrum at the backof the boiler. Fromthence it passes through and round the air-heate and escapes to the chimney-outlet-Ik.

From the air-heater tducts I pass below the middlelower water-drum'b, with connections leading to, first, the ash-pit second, the bridge; third, an. outlet above the door inside the furnace; fourth, outlets in side walls, if desired, these outlets being controlled by handles 1 on the boiler-front. In certain, cases I also combine with these air-ducts metal boxes w in the furnace-walls to further increase the temperature of the air supplied and cause better admixture of the furnace-gases, as illustratedin Figs. 13 and 14.

These metal boxes consist of chamber-shapedcastings w, open on one-side and with suitable perforations w in the bottom to admit air. These boxes are fixed in or against the furnace-wallst and through their open sides are inserted a number of metal plates or gills min contact at their outer edges with the furnace and-having their lower edges on orabout the furnace-level. These gil vided with suitable holes and slots, are locked s, which are. pro- Ibo and secured in their places by a bolt y or other device, and by means or theslots one or more gills may'be' removed and replaced without disturbing the othe'rs. Air-passages are arranged communicating from.the ash pit or cavity below the grate to the aforesaid perforations, these passages being closed when desired by suitable dampers. Thus air ad-- mitted from the ash-pit these. passages through the perforations and bGtWGQIltlIQ: gillsbecomes highly heated and assists to promote the better combustion of the gases The upper or steam drum 0, of this boiler is supported in semicirbutarcradles m. lhe lower drums of this boiler hang freely; but opposite to each manhole is a metal ring or frame 0 in the casing,with an iron door iitted to it, which I sometimes make with an aircharnber to prevent any leakage into or from the boiler-casing, as hereinafter described, and illustrated in Figs. 5, 6, 7, and 8. In this boiler I bring out certain tubes f from the front outer water-drum (above the fire-door) and from the lower middle water-drum, so as. to form tubular side walls to thc'furnace. Thus instead of only having heating-surface on one side of the fire, as is the ease in boilers of the Babcock and Stirling type, in this boiler there are water-tubes all round the fire in the eombustion-chamber. The side walls p, where of brick, are brought out'bclow these side tubes, so as to protect their under sides. I also (where no superhcater is used) sometimes bring the two outer rows of tubes in thisboiler at the front and'baek into line, so as to form one nearly-continuous wallof water-tubes at the front and back of the boiler for the better interception of the heat.

Where a superheater is used, I leave the outer tubes wide enough apart for the tubes of this to pass between the tubes of the boiler, as shown in Fig. 3.

The superheater referably employed is one consisting of a rum q, having loops of tubes 1' depending therefrom. Alight iron removable box 8 1s fitted over the ends of one side of the tube-loops inside the superhcaterdrum, fromwhich a pipe 25 conveys the superheated steam away. In some cases I construct this box s like an inverted trough, as

shown in Figs. 9 and 10, causin it'to'iit into two angle irons or castings 1n the interior of the superheater-drum, which angle-irons are joined at the ends by plates covering the 0 en ends of the trough when it is in position, t iis trough or box being pressed into and held in position by screws 2 assing through. the shell of the superheaterum. 4 In other cases I replace this trough s by short sections of plate either curved or flat bolted to the two angle-irons and to each other, as shown in Figs. 11 and 12.-- I

The superheatcr as contrived can be put either at the furnace or air-heater side of the steam-drum, so as to give either a high or a low superheat, and the boiler can be soconstrueted that the superheater canbe readily changed from one position to the other, A s Uecial aeeess or manhole door (illustrated in ms. 5 6

7, and 8) is used on this boiler to intercept as' far as possible heat radiation and leakiige of" air or gases. The framing of the doc r is acircular 11'011 ring 1, having an 'nner ledgeywilh certain lugs 2 about it, and an utor ledge. Against the inner ledge a circular sheet-iron door 3 is iitted by means of wedge-shaped pieces 4, fastened to it, tightening against the lugs or other suitable fastening, and against the outer ledge another dished door 5 is secured by means of a screw 6, attached to a swinging cross-bar .7. Thus the door includes an airchamber. Feed-water is admitted .to this boiler by pumping it into the back outer water-drum d through the feed v valve-d, whence it ascends .into the main steam-drum a by the tubes. in the back row.

In order to prevent priming, the steam is taken from the main steam-drum at, either by a number of small stop-valves u,place d.in various positions on the drum, so that there is no heavy draw of steam over any one partof the water-surface, or by a number ofsmall steam-pipes '0, led about inside the steamdrum, converging to one central stop-valve.

I put at the backand front of the boiler a layer of brick or non-conducting material resting on the tubes, and againstthis an outer casing, leaving an air-chamber between the two casings. As" the side walls are also cavity-wal ls, thcreis thus a double casing on all four sides of the boiler.

What I do claim, and desireto secure by Letters Patent, is

1. In steam-generators of the water-tube type, the combination with an upper steamdrum, afthree lower or water drums, b, c, d,

the central and lowest water-drum, 6, being connected to the steam-drum by tubes, e, and tubes, f respectively, the front water- 'druin being'connected to the steam-drum, a, by tubes, f, and f respectively, and the back water-drum, (l, by the tubes,f, of a fire-grate, it, placed and arranged transversely between the front and middle water-drums, an outlet for the )roducts of combustion arranged between the rear and middle water-drums and balllcs, j, placed and arranged for directing the course of the gases, in the manner and for t N) scribed.

'2. In steam-generators of the water-tube type, the combination with an upper steamdrum, three lower parallel water drums, tubes conneetingthe three water-drums with the steam-drum, and suitable baffle-plates between the drums, a fire-grate arranged between the front and middle water-drums, an outlet for the products of combustion arranged betwcen the middle and rear water 1 IO purposes substantially as herein de-.

(lru1ns,'and an air-heater in the said outlet tween the front and middle Water-drums, In witness whereof I have hereunto set my fuel door beneath the front drum, an outlet hend in presence of two witnesses.

for the pro; note of combustion arran 'ed bey tween the middle end rear water-drums, and R'LUUU Vl ILLS an air-heater in the said outlet and a passage I \Vitnesses:

leading from the air-heater to beneath the W. ll. BAJRSTO,

x Y J. F. Bum. 

